If you’ve ever dealt with stubborn pain around a tendon—maybe in your elbow, knee, shoulder, or Achilles—you’ve probably heard a bunch of different terms thrown around: tendonitis, tendinopathy, tendinosis.
Here’s the problem: most people (and honestly, even a lot of medical providers) use these terms interchangeably. But they don’t actually mean the same thing. And if you don’t understand what’s really going on with your tendon, you might be trying to treat it the wrong way.
As performance physical therapists here in Wilmington, we work with athletes and active adults who want to stay in the game, not sit on the sidelines. And tendon issues? They’re one of the most common reasons people end up frustrated, confused, and sometimes even considering surgery when they don’t need to.
Let’s clear up the confusion once and for all.
Before we jump into definitions, let’s take a quick step back. Tendons are the tough connective tissues that attach muscle to bone. When you contract a muscle, the tendon transmits that force to the bone so you can move.
In other words: without tendons, you don’t move.
The catch? Tendons don’t have the same blood supply as muscles. That means when they’re irritated, overloaded, or injured, they take longer to heal. And when healing is misunderstood, you end up stuck in a cycle of pain and failed treatments.
The suffix -itis literally means inflammation. Tendonitis refers to an acute inflammatory response in the tendon.
This usually happens in the early stages of tendon overload—think after a sudden spike in training volume, new exercises, or poor recovery. For example:
Key features of tendonitis:
Healing time:
With proper load management, acute tendonitis can often calm down in 2–6 weeks.
How PT helps:
If tendonitis isn’t addressed—or if you keep pushing through pain—acute inflammation can transition into tendinosis.
The suffix -osis means degeneration. In tendinosis, the tendon fibers themselves begin to break down. Think of it as the tendon losing its normal, healthy structure. Instead of strong, parallel collagen fibers, the tendon starts looking more disorganized and weaker under a microscope.
Key features of tendinosis:
Healing time:
Because tendons heal slowly, tendinosis can take 3–9 months, depending on severity and how well you manage load and rehab.
How PT helps:
Here’s where it gets confusing. Tendinopathy is the general term for any tendon pain or dysfunction. It’s basically the “catch-all” word.
If someone says “patellar tendinopathy,” they’re not specifying whether it’s acute inflammation (tendonitis) or degenerative changes (tendinosis). They’re just saying: this tendon is irritated and not happy.
Why does this matter? Because lumping everything under “tendinopathy” can cause people to treat it incorrectly. If you’re dealing with early tendonitis, you need short-term load management. If you’re dealing with tendinosis, you need long-term progressive strengthening.
The biggest mistake people make is trying to “stretch it out” or resting completely without building tendon capacity back up. Tendons need load to remodel and heal—but the right kind, at the right time.
At Conquer Movement, here’s how I help athletes and active adults get back to doing what they love—even when tendon pain is stubborn:
Tendon pain doesn’t have to be confusing. Understanding the difference between tendonitis, tendinosis, and tendinopathy is the first step toward real recovery.
👉 Tendonitis = short-term inflammation
👉 Tendinosis = long-term degeneration
👉 Tendinopathy = general tendon pain, could be either
The key is knowing where you are in the process—and treating it the right way.
If you’ve been stretching, resting, or even taking anti-inflammatories without progress, it’s time to take a different approach.
We offer a free discovery call for athletes and active adults in the Wilmington area. We’ll talk about what you’re experiencing, figure out the likely cause, and map out the first steps toward recovery.
Don’t waste another season battling tendon pain. Let’s get you back to moving, training, and performing at your best.
📞 Click here to schedule your free discovery call today.
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Dr. Evan Langley DPT, PT, CSCS
Performance Physical Therapist
Conquer Movement - Wilmington, NC